Editing Gadsden Purchase (section)

=== Railroad development ===
[[File:Gadsden Purchase Southern Pacific.jpg|thumb|upright=1.3|Gadsden Purchase]]

In 1846, James Gadsden, then president of the [[South Carolina Railroad]], proposed building a transcontinental railroad linking the Atlantic at Charleston with the Pacific at San Diego.<ref>{{cite book |last1=Schwantes |first1=Carlos |title=The West the Railroads Made |date=2008 |publisher=University of Washington Press |location=Seattle |isbn=978-0295987699 |page=16}}</ref> Federal and private surveys by Lt. John G. Parke and Andrew B Gray proved the feasibility of the southern transcontinental route, but sectional strife and the Civil War delayed construction of the proposed railroad. The [[Southern Pacific Transportation Company|Southern Pacific Railroad]] from [[Los Angeles]] reached Yuma, Arizona, in 1877, [[Tucson, Arizona]] in March 1880, [[Deming, New Mexico]] in December 1880, and [[El Paso, Texas|El Paso]] in May 1881, the first railroad across the Gadsden Purchase.<ref>{{cite book |first = David |last = Devine |title = Slavery, Scandal, and Steel Rails: The 1854 Gadsden Purchase and the Building of the Second Transcontinental Railroad Across Arizona and New Mexico Twenty-Five Years Later |year = 2004 |location = New York |publisher = iUniverse }}</ref>

At the same time, 1879–1881, the [[Atchison, Topeka and Santa Fe Railway|Atchison, Topeka and Santa Fe Railroad]] was building across New Mexico and met the Southern Pacific at Deming, New Mexico March 7, 1881, completing the second transcontinental railroad (the first, the central transcontinental, was completed May 10, 1869 at [[Promontory, Utah|Promontory Summit, Utah]]). Acquiring trackage rights over the SP, from Deming to Benson, the Santa Fe then built a line southwest to Guaymas, Sonora, Mexico, completed October 1882, as its first outlet to the Pacific. This line was later sold to the Southern Pacific. The Southern Pacific continued building east from El Paso, completing a junction with the Texas & Pacific in December 1881, and finally in 1883, its own southern transcontinental, the Sunset Route, California to New Orleans, Atlantic waters to the Pacific.<ref>{{cite book |last1=Myrick |first1=David |title=Railroads of Arizona, vol 1, the Southern Roads |date=1975 |publisher=Howell North |location=Berkeley, California |isbn=0-8310-7111-7 |pages=[https://archive.org/details/railroadsofarizo01myri/page/61 61–62] |url=https://archive.org/details/railroadsofarizo01myri/page/61 }}</ref> These railroads caused an early 1880s mining boom in such locales as [[Tombstone, Arizona]], [[Bisbee, Arizona]], and [[Santa Rita, New Mexico]], the latter two world class copper producers. From Bisbee, a third sub-transcontinental was built across the Gadsden Purchase, the [[El Paso and Southwestern Railroad]], to El Paso by 1905, then to a link with the Rock Island line to form the Golden State Route. The EP&SW was sold to the Southern Pacific in the early 1920s.<ref>{{cite book |title=Ibid.}}</ref>

The portion of the Southern Pacific in Arizona was originally largely in the Gadsden Purchase but the western part was later rerouted north of the Gila River to serve the city of Phoenix (as part of the agreement in purchasing the EP&SW). The portion in New Mexico runs largely through the territory that had been disputed between Mexico and the United States after the Treaty of Guadalupe Hidalgo had gone into effect, and before the time of the Gadsden Purchase. The [[Atchison, Topeka and Santa Fe Railway|Santa Fe Railroad Company]] also completed a railroad across [[Northern Arizona]], via [[Holbrook, Arizona|Holbrook]], [[Winslow, Arizona|Winslow]], [[Flagstaff, Arizona|Flagstaff]] and [[Kingman, Arizona|Kingman]] in August 1883.<ref>{{cite web |url=http://www.railswest.com/secondtranscontinental.html |title=Second Transcontinental Line brings competition |work=Railswest.com |access-date=May 28, 2011}}</ref> These two transcontinental railroads, the Southern Pacific (now part of the [[Union Pacific Railroad]]) and the Santa Fe (now part of the [[BNSF Railway|BNSF]]), are among the busiest rail lines in the United States.

During the early twentieth century, a number of short-lines usually associated with mining booms were built in the Gadsden Purchase to Ajo, Silverbell, Twin Buttes, Courtland, Gleeson, Arizona, Shakespeare, New Mexico, and other mine sites. Most of these railroads have been abandoned.<ref>{{cite book |last1=Myrick |first1=David |title=Railroads of Arizona, vol 1, the Southern Roads |date=1975 |publisher=Howell North |location=Berkeley, California |isbn=0-8310-7111-7 |pages=[https://archive.org/details/railroadsofarizo01myri/page/ passim.] |url=https://archive.org/details/railroadsofarizo01myri/page/ |url-access=registration }}</ref>

The remainder of the Gila Valley pre-Purchase border area was traversed by the [[Arizona Eastern Railway]] by 1899 and the [[Copper Basin Railway]] by 1904. Excluded was a {{convert|20|mi|km|adj=on}} section {{coord|33.1|N|110.6|W}} in the [[San Carlos Apache Indian Reservation]], from today's [[San Carlos Lake]] to [[Winkelman, Arizona|Winkelman]] at the mouth of the [[San Pedro River (Arizona)|San Pedro River]], including the [[Needle's Eye Wilderness]]. The section of [[U.S. Route 60 in Arizona|US Highway 60]] about {{convert|20|mi|km}} between [[Superior, Arizona|Superior]] and [[Miami, Arizona|Miami]] via [[Top-of-the-World, Arizona|Top-of-the-World]] (this road segment is east of Phoenix, in the Tonto National Forest passing through a mountainous region), takes an alternate route (17.4 road miles) between the [[Magma Arizona Railroad]] and the Arizona Eastern Railway railheads on each side of this gap. This highway is well north of the Gadsden Purchase.<ref>{{cite map |first= Marc |last= Pearsall |year=2002 |url=http://www.azrymuseum.org/Information/Arizona_Railroad_Map_2002.pdf |title=Railroads of Arizona |scale=Scale not given |location=Chandler |publisher=Arizona Railway Museum |access-date=August 1, 2008 }}</ref><ref>{{cite map |author=DeskMap Systems |year=2005 |url=http://www.arizonaeasternrailway.com/images/AZER%20Map.pdf |title=Arizona Eastern Railway |scale=Scale not given |location=Austin, TX |publisher=DeskMapSystems |access-date=August 1, 2008 |archive-url=https://web.archive.org/web/20060603235649/http://www.arizonaeasternrailway.com/images/AZER%20Map.pdf |archive-date=June 3, 2006 |url-status=dead |df=mdy-all}}</ref> Given the elevations of those three places, at least a 3% [[Grade (slope)|grade]] would have been required for rails built here, rather than the final alignment; railroads prefer 1% or less grade for better operation.<ref>{{cite news |url=http://trn.trains.com/railroads/abcs-of-railroading/2006/05/grades-and-curves |title=Grades and curves: Railroading's weapons in the battle against gravity and geography |last=McGonical |first=Robert S. |journal=Trains |date=May 1, 2006 |access-date=July 8, 2018 |archive-date=July 9, 2018 |archive-url=https://web.archive.org/web/20180709035205/http://trn.trains.com/railroads/abcs-of-railroading/2006/05/grades-and-curves |url-status=dead }}</ref> This rugged terrain above the Gila River confirms the engineering, technical wisdom of acquiring the Gadsden Purchase for a southern transcontinental railroad. To William H. Emory of the U. S. Army Corps of Topographical Engineers who surveyed the region in the 1840s–1850s, it was a good route "to the Pacific."<ref>{{cite book |last1=Borneman |first1=Walter |title=Rival Rails, the Race to Build America's Greatest Transcontinental Railroad |date=2010 |publisher=Random House |location=New York|isbn=978-1400065615 |page=8}}</ref>